TLV320AIC3212: Question about microphone array solution

Satoshi

Guru 19685 points

Customer is considering mic array solution for TLV320AIC3212 below.

Please let me know about below points.

①I think that TDM connection from the Host is below, is it correct?

　⇒MCK1(G1 pin), BIN1(J1 pin： Serial Data In), BCLK1（H1 pin： TDM Clock）, DOUT1（H2 pin： Serial Data Out）， WCLK1（J2 pin：Frame_Sync）

②Is TLV320AIC3212 not need external X-tal? 　(This device is only need MCLK input by MCU.)

③About application note slau360;

On the Table 2-2, Is GPIO2's Digital Mic Ckock equal to PDM clock?

　If PDM clock correct, can mic data receive below timing?

　⇒Clock rise: PDM-L, and clock fall:PDM-R

④Can Mic data(×8) send to MCU by TDM below image?

WCLK1,BCLK1,DIN,DOUT -----------<TDM Bus>-------------- MCU(Mic data ×8)

GPIO2---------------------------<PDM Clock>-----------MEMS Mic（1～8）

MCLK2---------------------------<PDM Data>-------------MEMS Mic（1～2）

DIN2----------------------------<PDM Data>-------------MEMS Mic（3～4）

GPIO1---------------------------<PDM Data>-------------MEMS Mic（5～6）

GPI1----------------------------<PDM Data>-------------MEMS Mic（7～8）

⑤If unnecessary the charge pump function, are pins involved in charge pump left open or GND, OK?

Best regards,

Satoshi

over 9 years ago

0 Luis Fernando Rodriguez S. over 9 years ago

TI__Guru* 84915 points

Satoshi-san,

First of all, the TLV320AIC3212 cannot handle up to 8 digital microphones at time. As described in the Reference Guide, the TLV320AIC3212 supports mono or stereo digital microphones. This means that it is only possible to handle up to two digital microphones. Even with the TDM mode, the TLV320AIC3212 only supports two ADCs and two DACs, which means that only two digital microphones can be used.

Regarding your questions above, please see my answers:

1) That's correct. The TDM connections would be as you mentioned:
⇒MCK1(G1 pin), BIN1(J1 pin： Serial Data In), BCLK1（H1 pin： TDM Clock）, DOUT1（H2 pin： Serial Data Out）， WCLK1（J2 pin：Frame_Sync）

2) There's no need to use an external X-tal. It is only necessary to send a MCLK signal from an external processor to the TLV320AIC3212. The audio codec can generate the BCLK and WCLK pulses from it.

3) GPIO2 can be used as digital microphone clock. Mic data can be as you mentioned:
　⇒Clock rise: PDM-L, and clock fall:PDM-R

4) As mentioned before, the TLV320AIC3212 only can handle up to two digital microphones.

5) Pins involved with charge pump can be left floated if it is not used.

Best regards,
Luis Fernando Rodríguez S.

Audio

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TLV320AIC3212: Question about microphone array solution